\begin{tikzpicture}[>=Stealth]
    \draw [->] (-1.0,0) -- (2*pi +1,0) node[anchor=north] {$x$};
    \draw [->] (0,-1.0) -- (0,2.5) node[anchor=east] {$y$};
    \node at (-0.3,-0.3) {$O$};
    \foreach \x / \name in {
        0.5*pi / $\dfrac \pi 2$,
        pi / $\pi$,
        1.5*pi / $\dfrac {3\pi} 2$,
        2 * pi / $2\pi$
    } {
        \draw (\x,0.2) -- (\x,0) node[anchor=north] {\name};
    }
    \foreach \y in {1,2} {
        \draw (0.2,\y) -- (0,\y) node[anchor=east] {\y};
    }

    \foreach \x / \y in {0 / 1, 0.5*pi / 2, pi / 1, 1.5*pi / 0, 2*pi / 1} {
        \fill (\x, \y) circle[radius=2pt];
    }
    \draw[domain=0:2*pi,samples=100] plot (\x, {1 + sin(\x r)}) +(-1.4, +1.3) node {$y = 1 + \sin x \quad x \in [0, 2\pi]$};
\end{tikzpicture}
